Revert 114494 - Remove BindStateHolder and have Bind() return a Callback<> object directly.

base/cancelable_callback.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // CancelableCallback is a wrapper around base::Callback that allows
 // cancellation of a callback. CancelableCallback takes a reference on the
 // wrapped callback until this object is destroyed or Reset()/Cancel() are
 // called.
 //
 // NOTE:
@@ skipping 155 matching lines @@
 
     callback_ = callback;
   }
 
   // Returns a callback that can be disabled by calling Cancel().
   const base::Callback<void(A1)>& callback() const {
     return forwarder_;
   }
 
  private:
-  void Forward(A1 a1) const {
+  void Forward(
+      typename internal::CallbackParamTraits<A1>::ForwardType a1) const {
     callback_.Run(a1);
   }
 
   // Helper method to bind |forwarder_| using a weak pointer from
   // |weak_factory_|.
   void InitializeForwarder() {
     forwarder_ = base::Bind(&CancelableCallback<void(A1)>::Forward,
                             weak_factory_.GetWeakPtr());
   }
 
   // Used to ensure Forward() is not run when this object is destroyed.
   base::WeakPtrFactory<CancelableCallback<void(A1)> > weak_factory_;
 
   // The wrapper closure.
   base::Callback<void(A1)> forwarder_;
 
   // The stored closure that may be cancelled.
   base::Callback<void(A1)> callback_;
 
   DISALLOW_COPY_AND_ASSIGN(CancelableCallback);
 };
 
 typedef CancelableCallback<void(void)> CancelableClosure;
 
 }  // namespace base
 
 #endif  // BASE_CANCELABLE_CALLBACK_H_